Cooling device for a fuel cell

ABSTRACT

One part of the primary cooling liquid drained from the primary heat exchange device  3  is let flow in the ion exchange device  15  through the communication passage  11 B, in which the flow rate of the primary cooling liquid to flow in the ion exchange device  15  by the flow rate regulator  14  is adjusted in uniformity. Accordingly, even if the electricity demanded for the fuel cell increases and decreasing, it is possible to manage conductivity in the primary cooling liquid and to offer the cooling device for the fuel cell reducing useless consumption energy to the utmost

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a cooling device for a fuel cell which can suitably cool off.

[0003] 2. Prior Art

[0004] Recently, there has been developed every kind of a battery car carrying on a motor for traveling replacing with an engine.

[0005] As one of these battery cars, a development of a fuel cell car which carries a hydrogen ion (or a proton) exchange membrane type fuel cell that is abbreviated to PEMFC (Proton Exchange Membrane Fuel Cell) as the power supply of a motor for traveling is advanced rapidly. (the cell is, hereinafter, referred to as a PEM type fuel cell)

[0006] This PEM type fuel cell is formed or constructed as stacks that laminate a cell a lot as a power generation unit. Each cell has the structure constituted, in which there is Membrane and Electrode Assembly (MEA) sandwiched between two separators, one of which is an anode side separator having a hydrogen supply channel or a cathode side separator having an oxygen supply channel.

[0007] Hereupon, as for the MEA, the anode side electrode catalyst layer and the gas diffusion layer are laminated successively on one side of the proton exchange membrane, and the cathode side electrode catalyst layer and the gas diffusion layer laminate successively on the other side of the proton exchange membrane.

[0008] And, to the fuel cell car carrying a fuel cell, such as the PEM type fuel cells, the cooling device to maintain a fuel cell at fixed right temperature range is arranged.

[0009] As for the cooling device, there is a reference of Japanese patent application 2000-155619, in which this patent applicant mentioned it in order to prevent a liquid junction phenomenon from occurring in a fuel cell. An outline of constitution of this cooling device is shown in FIG. 6.

[0010] At this cooling device 50, there are a primary circulating passage 51 for a primary cooling system and a secondary circulating passage 52 for a secondary cooling system formed, through those which the primary cooling liquid or the secondary cooling liquid is respectively circulated. And the primary cooling liquid has the fuel cell FC cooled, accordingly wormed primary liquid is cooled by the secondary cooling liquid through a heat exchanger 58 where both the primary and the secondary cooling passages pass through.

[0011] As for the primary circulating passage 51, there are provided with, first, a primary circulating pump 53 by which an insulating primary cooling liquid is pressed to be passed through the primary circulating passage 51, second, a heat regulator 54 which is, for example, composed of a thermostat. And an ion exchange device 55 also is there in order to remove various ion, such as metal ions or the like contained in the primary cooling liquid.

[0012] Besides, as for the secondary circulating passage 52, there are provided with a secondary circulating pump 56 by which an the secondary cooling liquid is pressed to be passed through the secondary circulating passage 52, and a radiator 57 to cool the second cooling liquid.

[0013] In this cooling device 50, there is the constitution provided, in which the primary cooling liquid is directly supplied to an electrode of fuel cell FC. Accordingly, when there are various ions such as metal ions existing in the primary cooling liquid, the electric insulation activity thereof is deteriorated, due to the conductivity thereof being raised remarkably.

[0014] In the cooling device 50, there is an ion exchange device 55 for the primary circulation passage 51 provided, by which various ions existing in the primary cooling liquid are removed in order to prevent it from deteriorating in such an electric insulation activity.

[0015] However, as for passing the primary liquid through the ion exchange device 55, because the internal pressure or resistance therefor is big, it is not appropriate for passing the whole of the primary cooling liquid through both the fuel cell and the ion exchange device 55 as in series.

[0016] Accordingly, there is arranged the ion exchange device 55 formed in parallel to the fuel cell FC and separated one part of whole of the first cooling liquid was passed in the ion exchange device 55.

[0017] Hereupon, it is necessary for the primary cooling liquid to be let flow more than one fixed quantity thereof through the ion exchange device 55 in order to manage the electric conductivity of the primary cooling liquid in conventional cooling device for the fuel cell 50 mentioned above.

[0018] However, when the fuel cell FC is used as a power supply of a car, because the electric power demanded for the fuel cell is changed in various ways by large range according to each running state thereof or the like, a flow rate of the primary cooling liquid is also let be changed according to a change of electric power demanded for this fuel cell FC. Namely, the flow rate of the primary cooling liquid is let be increased, when the demand electricity for the fuel cell FC increases, because the fuel cell FC must be cooled all the much.

[0019] Contrariwise, the flow rate thereof is let be decreased, when the demand electricity for the fuel cell FC decreases.

[0020] Hereupon, in conventional device 50 said forgoing, the increase or the decrease of the flow rate of the primary cooling liquid is to be adjusted by the pressure pressed at the primary circulating pump 53.

[0021] Besides, the quantity of the primary cooling liquid supplied in the ion exchange device 55 also depends on the pressure pressed by the primary circulation pump 53.

[0022] Therefore, when the demand electricity for the fuel cell FC is small, because the pressure pressed by the prime circulation pump 53 is also let become small, there becomes a little flow rate of the primary cooling liquid in the ion exchange device 55.

[0023] Accordingly, when the electric power demanded for the fuel cell is small, there may be the case that the enough flow quantity cannot be secured therein (55) to measure and control the electric conductivity of the primary cooling liquid.

[0024] In order to solve the problem, it is good if the primary circulation liquid of necessary quantity to measure the electric conductivity is supplied or secured in the ion exchange device 55 by virtue of a certain method with a little demanded electricity for the fuel cell.

[0025] However, when the demand electricity for the fuel cell is big, the primary circulation liquid than need is supplied in the ion exchange device by using this method and then, the energy to drive the primary circulation pump 53 has been to be used idly.

[0026] Consequently, as for an object of this invention, even if the demanded electricity for the fuel cell is increased or decreasing, and the flow rate of the primary cooling liquid supplied in the fuel cell is increased or decreasing, there is the cooling device for the fuel cell offered in the world, in which it is possible to have the electric conductivity controlled in the primary cooling liquid and the useless consumption of energy is reduced to the utmost as far as it can be.

SUMARY OF THE INVENTION

[0027] The present invention solved the subject mentioned above is the cooling device for the fuel cell characterized by that in which cooling system the cooling liquid circulated and supplied to the fuel cell for cooling thereof, there are comprising: a circulating pump, through which said circulating liquid is let circulate; a heat exchanger, in which the cooling liquid excreted from said fuel cell is cooled; an ion exchange device or container made of ion exchanging resin, through which ions are removed from the cooling liquid; a flow rate or quantity adjustment device that the constant, flow quantity to flow into the ion exchange device is kept.

[0028] In this invention according to claim 1, because there is the flow rate adjustment means arranged, through which the flow rate of the primary cooling liquid flown through the ion exchange device is kept in constant, the flow rate thereof through the ion exchange device can be adjusted in a suitable constant range in all flow rate of the primary cooling liquid originated in the primary circulating pump.

[0029] Therefore, as for the primary circulating pump, because it is not impossible that the pressure pressed through it is set up on the base of the same when the flow rate of the primary circulating liquid is the most little, useless energy consumption can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is a circuit constitution view of the cooling device of a fuel cell car concerned with the first embodiment of this invention.

[0031]FIG. 2 is a cross sectional view showing the flow rate regulator of this invention.

[0032]FIG. 3 is a local sectional view showing the cell structure of the fuel cell shown in FIG. 1.

[0033]FIG. 4 consists of (a) and (b), in which (a) is a graph showing the relation between power of a fuel cell and a flow rate of the primary cooling liquid passing through the ion exchange device of conventional cooling device for a fuel cell, (b) is a graph showing the relation between power of a fuel cell and a flow rate of the primary cooling liquid passing through the ion exchange device of the cooling device for a fuel cell according to this invention.

[0034]FIG. 5 is a circuit constitution view of the cooling device of the fuel cell car concerned with the second embodiment of this invention.

[0035]FIG. 6 is a circuit constitution view of the cooling device of the fuel cell concerned with prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0036] This invention will be described concretely in further detail with reference to the accompanying drawings. FIG. 1 is a constitution view of the cooling device for a fuel cell according to the first embodiment of the present invention. FIG. 2 is a cross sectional view showing the flow rate regulator of this invention. FIG. 3 is a local sectional view showing the cell structure of the fuel cell shown in FIG. 1.

[0037] As shown in FIG. 1, the cooling device M1 for a fuel cell according to this embodiment has a primary cooling system 1, through which the primary cooling liquid to cool fuel cell FC circulates and a secondary cooling system 2 as well. These primary and secondary cooling systems are connected with each other through a heat exchanger 3.

[0038] In the primary cooling system 1, the primary circulation passage 11 is formed. The primary circulation passage 11, which comprises the primary circulation pump 12 to cycle the primary cooling liquid in the primary circulation passage11 and a thermostat which for example, keeps a three way valve, and is provided with the heat regulator 13

[0039] Besides, the primary circulation passage 11 is provided with the flow rate or quantity regulator 14 as a flow rate adjustment means, through which the primary cooling liquid is let flow therein with a constant flow rate maintained, and the ion exchange device 15 that contains the ion-exchange resin, which removes various kinds of ions, such as metal ions contained by the primary cooling liquid.

[0040] As for the primary cooling passage 11, it is constituted a circulation passage, through which the primary cooling liquid firstly passed by the primary circulation pump 12 passes through the heat exchanger 3, a cooling liquid channel C12 (FIG. 3) of the fuel cell (FC), and comes back to the primary circulation pump 12.

[0041] There is formed a heat regulator 13 in the space between the heat exchanger 3 and the primary circulation pump 12, those which respectively are connected with each other through the flow passage.

[0042] At this point, there is formed a bypass passage 11A stood in a row with the heat exchanger 3, through which the cooling liquid originated in the primary circulation pump 12 flows toward the heat exchanger 3 and separating in two ways at the starting point of the bypass passage before, and to the heat regulator 13

[0043] the point of span between

[0044] The heat regulator 13 is composed of the well-known thermostat, which comprises a member expanded by the heat, in which both the primary cooling liquid wormed in the fuel cell and the same cooled in the heat exchanger 3 flow respectively through the bypass passage 11A or from the heat exchanger 3.

[0045] Through this member thereof (13), the inflow ratio of the wormed liquid to the cooled liquid, which flow therein is let change or adjust, by letting the cross-section area that corresponds to each flow rate thereof change.

[0046] Consequently, there is the primary cooling liquid adjusted by temperature of around 70° C. flown out in the primary circulation passage.

[0047] When the electricity output demanded from the fuel cell increases, because it is necessary to cool the more the fuel cell FC, a plenty of the primary cooling liquid is in control of circulating therein.

[0048] On the contrary, when the same decreases, because it is good for cooling the fuel cell FC the less, the first cooling liquid to cycle it with the first circulation pump 12 is controlled in a small quantity.

[0049] In this way, the flow quantity of the first cooling liquid to cycle with the first circulation pump 12 is controlled according to size of the electricity output demanded from the fuel cell FC.

[0050] Besides, as for the primary circulating passage 11, a communication passage 11B is also formed, which is connected with a point of passage between the primary circulation pump 12 and the fuel cell FC and stands in a row.

[0051] As for the communication passage 11B, there are a flow rate regulator 14 and the ion exchange and the ion exchange device 15 arranged in this order from the upper stream.

[0052] As to the flow rate regulator 14, as shown in FIG. 2, there is provided an inflow port14A communicated to the communication passage 11B.

[0053] The inflow port 14A is communicated to a space part 14B, in which there is formed a sleeve valve14C that can move in the flow direction of the primary cooling liquid. And there is formed a movable orifice 14D at the most upper part in the movable range of the sleeve valve 14C.

[0054] Moreover, there is formed a recess inside the sleeve valve 14C, where there is arranged a spring 14E that presses the sleeve valve 14C in the direction of the inflow port 14A.

[0055] Furthermore, there are arranged flow exits 14F formed on the both flank of the sleeve valve 14C, by which when the sleeve valve 14C gets closer to the inflow port 14A most, the space part 14B communicates with an outflow passages 14G perfectly. The outflow passages 14G communicates with the down stream side of the communication passage 11B.

[0056] Besides, there is an orifice for diminishing pressure 14H formed in the most down stream location of the space part 14B, which communicates with an outflow port 14I, that also communicates with the communication passage 11B.

[0057] At this point, as for the flow rate regulator 14, in which when the primary cooling liquid drained from the heat exchanger 3 (shown in FIG. 1) passes through the inflow port 14A and flows into the space part 14B, the sleeve valve 14C is let move and the opening area of the flow exit 14F through which the cooling liquid can flow to the outflow passages 14G is let adjust, so that the pressure difference at the point between before and after the regulator may be constant, namely that the flow rate difference thereat may be constant.

[0058] To be concrete, when the liquid pressure of the primary cooling liquid is smaller than the pressure given by the spring 14E, the sleeve valve 14C is located in the upper side of the stream, so that each opening area formed in the common opening part between the flow exits 14F and the outflow passages 14G is adjusted large.

[0059] Accordingly, a large quality of the primary cooling liquid flows through the flow exit 14F comparatively.

[0060] On the contrary, when the liquid pressure of the primary cooling liquid is larger than the pressure given by the spring 14E, the sleeve valve 14C moves to the down stream side.

[0061] With the movement to the down stream side of the sleeve valve 14C, each opening area formed between the flow exits 14F and the outflow passages 14G becomes small.

[0062] In this way, it is possible to keep the flow rate of the primary cooling liquid that passes through the communication passage 11B, because the opening area formed at each place between the flow exits 14F and the outflow passages 14G is adjusted, with the change of liquid pressure of the primary cooling liquid.

[0063] As for the orifice for diminishing pressure 14H, it is formed for the flow rate regulator 14 not to be damaged, because the space part 14B is suffered from the surplus liquid pressure when the sleeve valve 14C moves in side of most down stream and there is the flow passage intercepted completely at each place to which the flow exits 14F and the outflow passages 14G respectively.

[0064] Accordingly, the diameter of the orifice for diminishing pressure 14H is formed much smaller than that of the movable orifice 14D.

[0065] As for the flow rate regulator 14 formed in this matter, by which it is controlled that the flow rate of the prime cooling liquid supplied to the ion exchange device 15 is constant, at predetermined value. And the flow rate thereof passed through the communication passage 14B, to which a part of the primary cooling liquid flown via the heat regulator 13 is supplies, is also controlled constant.

[0066] As to the ion exchange device 15, there is the ion exchange resin (not shown) possessed, with which the primary cooling liquid is contacted, and by which various kinds of ions such as metal ions dissolved in the primary cooling liquid are absorbed and removed therein.

[0067] The primary cooling liquid to contain the bypass passage 11A and the communication passage 11B is accommodated in a fuel cell box (not shown), and the heat exchanger 3 as well.

[0068] The heat exchanger 3 is arranged in a neighborhood of the fuel cell FC, and, accordingly, as for the prime circulation passage 11, the length of duct line thereof is shortened.

[0069] And, as for the primary circulation passage 11 let shorten, it is constituted materials that are suitable enough to prevent the liquid junction phenomenon from occurring in the fuel cell FC.

[0070] As being hard to elute ions therefrom, it is used for example, an insulator such as a glass coated stainless steel pipe, a synthetic resin pipe or the like.

[0071] Still more, the insulation refrigerant is used as the primary cooling liquid in order to prevent the liquid junction phenomenon from occurring in the fuel cell FC.

[0072] As for the insulation refrigerant, it is desirable to use a pure water that conductivity thereof is maintained low, or a mixture liquid of the pure water mentioned above and ethylene glycol series, but be able to use insulating oil.

[0073] On the other hand, there is a secondary circulation passage 21 formed in a secondary cooling system 2.

[0074] As for the secondary circulation passage 21, there are formed a radiator 23 to air-cool a secondary cooling liquid and a secondary circulation pump 22 to cycle the second cooling liquid in the circulation passage 21.

[0075] And, it is systematized that the secondary cooling liquid pressed by the secondary circulation pomp 22 passes through the heat exchanger 3 and a radiator 23 and come back to the secondary circulation pump 22.

[0076] Besides, the radiator 23 is that of air-cooling to possess the electric cooling fan (not shown).

[0077] Furthermore, as for the secondary circulation passage 21, it is constituted materials same as described in the primary cooling passage 11, being hard to elute ions therefrom in order to prevent the liquid junction phenomenon from appearing in the fuel cell FC.

[0078] As for materials mentioned above, there is used for example, an insulator such as a glass coated stainless steel pipe, a synthetic resin pipe or the like.

[0079] As for the secondary cooling liquid, there is used the insulation refrigerant of a pure water mentioned above or a mixture liquid of a pure water and ethylene glycol line in order to prevent the liquid junction phenomena from occurring in the fuel cell FC, same as the first cooling liquid.

[0080] Besides, as for the secondary cooling system 2, there is cooling not only the first cooling line 1 but also the other members in the fuel cell car that the fuel cell is carried in.

[0081] For example, heating sources which contain a motor for traveling, a drive motor for supercharger, a drive unit and a control unit or the like are cooled by cycling the secondary cooling liquid therein.

[0082] The secondary cooling liquid having cooled these devices so that being warmed is cooled in the radiator 23.

[0083] More, hereupon, it is controlled that a temperature of the primary cooling liquid in the primary cooling system 1 is in around 70° C., so that it may be controlled that the fuel cell FC is maintained in right temperature range of 75° C.˜85° C.

[0084] On the one side, as for the temperature of the secondary cooling liquid 2, it is maintained in around 75° C. at the place between the exit side of the heat exchanger 3 and the entrance side of the radiator 23, and it is maintained in around 65° C. at the place between the exit side of the radiator 23 and the entrance side of the heat exchanger 3.

[0085] Besides, as for the fuel cell FC, it is the PEM type fuel cell, in which a cell being a generation unit is laminating a lot, and there can be obtained a most stable output state in temperature environment of 75° C.˜85° C.

[0086] Hereupon, as shown FIG. 3, each cell constituting the fuel cell FC has the structure that a membrane/electrode assembly (MEA) C6 which has a seal C5 is put between a cathode side separator C2 having an oxygen supply road C1 in the inside and a anode side separator C4 to have a hydrogen supply road C3 in the inside.

[0087] As for this membrane/electrode assembly C6, a cathode side electrode catalyst layer C8 and a gas diffusion layer C9 are laminating successively on one side of a hydrogen ion exchange membrane C7, and an anode side electrode catalyst layer C10 and a gas diffusion layer C11 are laminating successively on the other side thereof.

[0088] And, in the outside of the anode side separator C4, a cooling liquid pass C12 is formed.

[0089] As mentioned above, as for the cooling device for the fuel cell according to this embodiment, there are the primary and the secondary circulation pumps (12or22) provided, by which respectively, the primary or the secondary cooling liquid is let cycle in the primary or the secondary circulating passage (11 or 12).

[0090] Hereupon, in case that the fuel cell is there in cold state, wherein the primary cooling liquid passed through the heat regulator 13 of the primary circulating passage 11 is low in temperature, because the primary circulation passage 11 in the heat regulator is cut at the point of exit side of the heat exchanger 3, the primary cooling liquid circulates from the primary circulation pump 12, through the bypass passage 11A, the heat regulator 13 and the cooling liquid pass C12, and comes back to the primary circulation passage 12.

[0091] And, since the primary cooling liquid circulated through the primary circulation passage without passing the heat exchanger 3 is let warm gradually in a stage of passing through the cooling liquid pass C12 of the fuel cell FC, the fuel cell FC is let be warming up.

[0092] When the temperature of the primary cooling liquid to pass through the heat regulator 13 of the primary circulation passage 11 is raised, and the warming up the fuel cell FC is completed, the heat regulator 13 controls an inflow ratio of the primary cooling liquid to flow from the bypass passage 11A and to flow from the heat exchanger 3, so that the mixture thereof may be adjusted in temperature of 70° C.

[0093] The primary cooling liquid adjusted in this way passes through the cooling liquid pass C12 of the fuel cell FC and is let take in the heat thereof by the process and cools the fuel cell FC so much.

[0094] Then, the primary cooling liquid cooled the fuel cell FC is cooled once again in the heat exchanger 3, because there is performed therein a heat exchange between the primary cooling liquid thereof and the secondary cooling liquid of the secondary circulation passage.

[0095] On the other hand, the secondary cooling liquid passes from the secondary circulation pump 22 in the secondary circulation passage 21, and flows into a radiator 23, then flows out of the radiator 23 and circulates to the second circulation pump 22.

[0096] And the secondary cooling liquid flowed into the heat exchanger 3 absorbs heat of the primary cooling liquid of the primary circulating passage 11 there and radiates heat in the air with blast of the radiator.

[0097] As controlled in this way, the temperature of second cooling liquid is, as stated forgoing, maintained in around 75° C. in entrance side of the radiator 23, and it is maintained in around 65° C. with the exit side of the radiator 23.

[0098] Besides, in the primary circulation passage 11, as for the primary cooling liquid including that cooled off in the heat exchange device 3, one part of which is controlled to supply in the ion exchange device 15 through the communication 11B.

[0099] At this point, it is controlled that the flow rate of the primary cooling liquid in the communication passage 11B becomes fixed through the flow rate regulator 14, namely the primary cooling liquid flown into the communication passage 11B also is adjusted to the fixed value in the flow rate.

[0100] On this account, the flow rate of the primary cooling liquid in the ion exchange device 15 becomes settled at a certain value, even if the output of the fuel cell FC is big, and the flow rate of the primary cooling liquid flown through the primary circulating passage 11 is large, due to enhancement of the pressure demanded for the primary circulating pump 12.

[0101] In the same matter, even if the output of the fuel cell FC is a little, and the flow rate of the primary cooling liquid flown through the primary circulating passage 11 is small due to the small pressure demanded for the primary circulation pump 12

[0102] Accordingly, there can be the useless consumption energy reduced, because it is not necessary that when there is a little flow rate of the primary circulation liquid, and setting the required pressure of the primary circulation pump 12 for the flow rate in the ion exchange device 15.

[0103] Hereupon, the relation of the flow rate of the primary cooling liquid flowing through the ion exchange device 15 with the output of the fuel cell FC is referred to accompanying FIG. 4.

[0104] As for the fuel cell FC and the ion exchange device 55, each of which is concerned with a current cooling device for the fuel cell FC, the relation between the output of the former and the flow rate of the primary cooling liquid flown in the latter is shown in FIG. 4(a).

[0105] Pressure pressed in the first circulation pump 53 depends on the electricity output of the fuel cell.

[0106] In other words, when the output demanded for the fuel cell FC increases, because the fuel cell is need to cool more, it is required that a lot of the primary cooling liquid is let pass through the same.

[0107] Contrariwise, when the output demanded for the fuel cell FC decreases, because the fuel cell is to cool a little, it is good for small quantity of the primary cooling liquid to pass through the fuel cell FC.

[0108] On this account, the flow rate QR of the first cooling liquid flowing through the ion exchange device 55 is almost in proportion to the output of the fuel cell FC.

[0109] In the ion exchange device 55, the flow rate QN, for which it is necessary to manage conductivity of the primary cooling liquid is almost fixed independently of output of the fuel cell FC.

[0110] Accordingly, in current cooling device 50, the flow rate of the primary cooling liquid to pass the ion exchange device 55 in the greater part of the output range of the fuel cell FC is small or lacked or is too big or a surplus adversely.

[0111] Because the flow rate regulator 14 is arranged with the cooling device M1 according to the present invention for this, as show in FIG. 4(b) and it is possible to do the flow rate QR of the primary cooling liquid to pass through the ion exchange device 15 with uniformity almost.

[0112] On this account, the flow rate of the primary cooling liquid in the ion exchange device 15 can be prevented from inclining to the surplus situation or that is short.

[0113] Besides, in the condition that the flow rate QR of the first cooling liquid in the ion exchange device 15 is a little more than the flow rate QN needed for managing conductivity of the primary cooling liquid, it is possible that the conductivity of the primary cooling liquid can be let manage

[0114] Besides, another embodiment according to the present invention will be described referring to FIG. 5.

[0115] Because the cooling device M2 according to this embodiment compared with the first embodiment mentioned above to show it in FIG. 5 and is different in only the primary cooling system 1, it is noted that there are same number used for the fuel cell FC, the secondary cooling system 2 and the heat exchange device 3 and the same explanation will be omitted.

[0116] The primary cooling device M2 according to this embodiment has the primary cooling system 4, and in which the primary circulation passage 41 is formed.

[0117] The primary circulation passage 41 possesses the primary circulation pump 42 to cycle the first cooling liquid in the circulation passage 41 and the heat regulator 43 which is for example, made from thermostat and can adjust temperature of the primary cooling liquid.

[0118] Besides, as for the primary circulation passage 41, it is provided with the flow rate regulator 44 that is the flow rate adjustment means to adjust it so that the flow rate becomes fixed and the ion exchange device 45 that the ion-exchange resin is used for and which removed various ions of metal ions contained in the primary cooling liquid.

[0119] Moreover, the flow rate regulator 44 and the ion exchange device 45 are formed in one united body.

[0120] As for the cooling device M2, that cooling device M2 miniaturized to the utmost is expected, so that it may be accommodated in limited space of the fuel cell box.

[0121] Accordingly, from this standpoint, this embodiment formed in a body is very useful.

[0122] The preferred embodiments according to the present invention are described , but this invention is not limited to the embodiments mentioned above.

[0123] For example, as the flow rate adjustment means, it is necessary not to use the flow rate regulator shown by the first embodiment mentioned above and it is possible to utilize the flow rate control means of common knowledge.

[0124] Consequently, as for the present invention, there is formed the flow rate regulator in the cooling passage, through which the cooling liquid pass to the ion exchange device of the fuel cell.

[0125] Accordingly, even if the flow rate of the cooling liquid which pass to the fuel cell is changed, due to no change of the flow rate thereof passed to the ion exchange device, it is possible to perform the ion exchange in stability. 

What is claimed is:
 1. A cooling device for a fuel cell, in which cooling system a cooling liquid is circulated and supplied to said fuel cell for cooling the same, there are comprising: a circulating pump, through which said cooling liquid is let circulate; a heat exchanger, in which the cooling liquid excreted from said fuel cell is cooled; an ion exchange device made of ion exchanging resin through which ions are removed from said cooling liquid; a flow rate adjustment device in which the constant, flow rate to flow into the ion exchange device is kept.
 2. A cooling device for a fuel cell according to claim 1, wherein Said ion exchange device and said flow rate regulator are formed in one combined body.
 3. A cooling device for a fuel cell according to claim 1 or claim 2, wherein said flow rate of the cooling liquid circulated by said circulating pump is controlled according to generated output of the fuel cell. 